a. Technical Field
The instant disclosure relates generally to power electronics systems, and more particularly to a hybrid switch including a GaN high electron mobility transistor (HEMT) and a silicon (Si) metal oxide semiconductor field-effect transistor (MOSFET).
b. Background
This background description is set forth below for the purpose of providing context only. Therefore, any aspects of this background description, to the extent that it does not otherwise qualify as prior art, is neither expressly nor impliedly admitted as prior art against the instant disclosure.
In a power electronics circuit, a high-current power capability can be provided by electrically connecting a plurality of semiconductor switches in a paralleled arrangement so as to permit the undertaking of the load current together. A paralleled arrangement is desirable because such a paralleled arrangement can collectively have a much lower conduction resistance as compared to a single switch. The reduced conduction resistance can reduce a conduction loss, which can increase an overall system efficiency. Silicon switches (e.g., MOSFET) are known for use in power applications; however, such switches are not operated at very high switching frequency due to relatively high switching losses.
Wide-bandgap (WBG) devices, such as Silicon Carbide (SiC) and Gallium Nitride (GaN) devices are becoming more popular due to their higher switching frequency capability, lower switching loss and higher thermal capability as compared to conventional silicon (Si) devices. However, WBG devices still have their own challenges.
First, its current capability compared to the Silicon devices is still not high enough for some applications. For such high-current applications, it is required to parallel multiple WBG switches, which increases the system cost. Second, particularly for a so-called GaN high electron mobility transistor (HEMT) device, its reverse conduction loss is much higher than, for example, a silicon MOSFET device when the switch is not “on”. This reverse conduction loss characteristic limits system efficiency.
There is therefore a need to overcome one or more of the problems in the art.
The foregoing discussion is intended only to illustrate the present field and should not be taken as a disavowal of claim scope.